If you’re looking for musical comfort food, Shooter Jennings’ late-’70s Southern-rock revivalism and homages to Daddy’s booming cranky-tonk country will do. But without a song half as great as the last album’s ”4th of July,” you can’t help but notice how closely and turgidly he’s adhering to those touchstones on Electric Rodeo, clichés about drink ‘n’ drugs ‘n’ the ruinous road included. At least ”Aviators” — an amusing ode to his retro shades — is consciously parodistic.